This document relates to an electrical switch, also known as a switch. The document describes a switch which might be used as a detect switch in the car vehicles field, for example in association with a door latch.
Electrical switches have been designed for selectively establishing at least a first conductive way between two conductive fixed contacts, the switch comprising a housing, and a pushbutton arranged so that, when an external force is applied to the pushbutton, the pushbutton is moved relative to the housing between a pushbutton position in which the conductive way is established; and a pushbutton position in which the conductive way is interrupted. This conductive way, and thus the switch, can be of the normally open (NO) type or of the normally closed (NC) type.
According to a known design, such a switch might be of the “snap switch” type such as illustrated in U.S. Pat. No. 2,743,331 or 3,098,905.
In such a design, the switch has a high current carrying capacity or ability, and long life duration. However, the “snapping” or “clicking” noise might be detrimental in some applications, as well as the presence of a hysteresis. A snap switch also has a limited over travel capacity.
According to another known design, the switch might be of the “slide switch” type such as illustrated in US Patent Application Publication Number 2011/0147186 in which a sliding contact arrangement is disclosed in combination with a snapping arrangement.
In such a design, there is no detrimental noise, neither any hysteresis. However, it cannot adequately carry medium or high currents and may have quite short life duration.
U.S. Pat. No. 6,753,489 discloses an electrical switch comprising a housing having a receiving portion, an actuation member comprising an actuating portion extending into the housing and arranged to be moved vertically between a pushbutton upper position and a pushbutton lower position; a pair of associated contact elements comprising a fixed contact element provided in the receiving portion; a movable contact element arranged facing the fixed contact element and that may come into contact with the fixed contact element for establishing a conductive switching way between the movable contact element and the fixed contact element; and an elastically deformable conductive blade in the form of a hairpin supported by the receiving portion. The blade comprises a movable active branch.
In U.S. Pat. No. 6,753,489, the active branch of the hairpin shaped blade is pivotally mounted with respect to the housing—around a horizontal pivotal axis—between a first active position in which a first switching way is established and a second switching way is interrupted, and a second active position in which the first switching way is interrupted and the second switching way is established.
To provoke the pivotal movement of the active branch, the actuating portion is in the form of a cam acting on the other branch of the hairpin shaped blade.
According to such a design, the pivotal movement of the active branch is providing a noisy snapping effect and in which the two switching ways cannot be controlled independently. Also, in case of medium or high currents, the “floating” design of the blade which globally moves as a whole, does not permit electrical connection of the blade to the outside of the switch.
This document describes an electrical switch that improves on the prior art by having a design that results in little or no hysteresis, that is relatively silent, and that can be designed for “make before break” or “break before make.” Also, optionally, the design may permit the carrying of medium or high currents.